Communications using unmanned surface vehicles and unmanned micro-aerial vehicles

ABSTRACT

A communications system and method utilizes an unmanned surface vehicle (USV) capable of collecting data about an environment in which the USV resides. At least one micro-aerial vehicle (MAV), equipped for unmanned flight after a launch thereof, is mounted on the USV. Each MAV has onboard radio frequency (RF) communications. Each MAV launched into the air transmits the data collected by the USV using the MAV&#39;s RF communications.

ORIGIN OF THE INVENTION

The invention described herein was made in the performance of officialduties by an employee of the Department of the Navy and may bemanufactured, used, licensed by or for the Government for anygovernmental purpose without payment of any royalties thereon.

CROSS-REFERENCE TO RELATED PATENT APPLICATIONS

This patent application is co-pending with one related patentapplication entitled “RECONNAISSANCE USING UNMANNED SURFACE VEHICLES ANDUNMANNED MICRO-AERIAL VEHICLES” Ser. No. 10/354,507, by the sameinventor as this patent application.

FIELD OF THE INVENTION

The invention relates generally to communications systems and methods,and more particularly to a method and system of communication usingunmanned surface vehicles and unmanned micro-aerial vehicles.

BACKGROUND OF THE INVENTION

A variety of unmanned surface vehicles (e.g., on the ground or watersurface) are used to sense/collect data about an environment in whichthey reside. The data is then transmitted to a base station using radiofrequency (RF) communications. However, the range of the RFcommunication is limited by the vehicle's line-of-sight due to itsground or water surface location. To improve the communication range,the vehicle could be equipped with satellite communications (or SATCOMas it is known) equipment. However, SATCOM equipment is big and heavy,consumes a lot of power, is expensive, is limited in bandwidth, and issubject to satellite availability and/or allocation problems.

SUMMARY OF THE INVENTION

Accordingly, it is an object of the present invention to provide amethod and system for improving communications from unmanned surfacevehicles.

Another object of the present invention to provide a method and systemfor improving communications from unmanned surface vehicles usingunmanned micro-aerial vehicles.

Other objects and advantages of the present invention will become moreobvious hereinafter in the specification and drawings.

In accordance with the present invention, a communications systemincludes an unmanned surface vehicle (USV) capable of movement on anearth surface. The USV has data collection means for collecting dataabout an environment in which the USV resides. At least one micro-aerialvehicle (MAV), equipped for unmanned flight after a launch thereof, ismounted on the USV. Each MAV has radio frequency (RF) communicationmeans mounted thereon. A launcher mounted on the USV is used to launcheach MAV into the air where each MAV so-launched transmits the datausing its RF communication means.

BRIEF DESCRIPTION OF THE DRAWINGS

Other objects, features and advantages of the present invention willbecome apparent upon reference to the following description of thepreferred embodiments and to the drawings, wherein correspondingreference characters indicate corresponding parts throughout the severalviews of the drawings and wherein:

FIG. 1 depicts an operational scenario of a system using an unmannedsurface vehicle and micro-aerial vehicles in accordance with the presentinvention where FIGS. 1A–1D depict a time progression in the operationscenario;

FIG. 2 is a functional block diagram of an unmanned surface vehicle foruse in the present invention;

FIG. 3 is a functional block diagram of an unmanned micro-aerial vehiclefor use in the present invention; and

FIG. 4 depicts another operational scenario in accordance with thepresent invention.

DETAILED DESCRIPTION OF THE INVENTION

Referring now to the drawings, and more particularly to FIGS. 1A–1D, anoperational scenario is depicted for a system that can carry outreconnaissance and/or communications in accordance with the presentinvention. For simplicity of description, each of the reconnaissance andcommunications aspects of the present invention will be explained asseparate operations. However, it is to be understood that the operationscould be combined and provided by one system.

With respect to the reconnaissance aspect of the present invention, anunmanned surface vehicle (USV) 10 is provided and is capable ofnavigated movement on a surface 100 of the earth. Surface 100 can be theground (to include dry land and the seafloor), or can be the surface ofa body of water. Accordingly, USV 10 can be a ground-based vehicle or afloating vehicle without departing from the scope of the presentinvention. USV 10 can navigate autonomously to a desired location or canhave its navigated movement controlled from a remote location.

Incorporated into or mounted on USV 10 is a launcher 12 for launchingone or more micro-aerial vehicles (MAV) 14 from USV 10. As is known inthe art, each MAV 14 is a small, unmanned aircraft (e.g., wingspan onthe order of 6 inches) capable of controllable flight using a gasolineor electric motor. See, for example, “New, Improved Plane Gives UF Tieat MAV Contest,” The Florida Engineer, Summer 2002. As will be explainedfurther below, each MAV 14 is equipped with video surveillance equipmentand wireless communication equipment, neither of which is shown in FIG.1 for clarity of illustration.

When commanded to do so, launcher 12 applies a sufficient force tolaunch one of MAVs 14 into the air at which point the onboard propulsionsystem (not shown in FIG. 1) of MAV 14 keeps it airborne. Given theminimal weight of each MAV 14, launcher 12 can be realized of a varietyof simple spring-loaded mechanical launchers (e.g., catapult),gas-powered launchers, or any other low-power launcher, the choice ofwhich is not a limitation of the present invention. Such launchers, arewell known in the art and, therefore will not be described furtherherein.

In operation, USV 10 navigates under autonomous or remote control to adesired location on earth surface 100 as shown in FIG. 1A. USV 10 couldremain on dry land at all times or could transition from a wetenvironment to a beach location for covert reconnaissance operations.When reconnaissance is needed, launcher 12 is commanded to launch one ofMAVs 14 into the air as illustrated in FIG. 1B. To check and initializesystems (e.g., flight propulsion and control systems, video surveillancesystems, communication systems, etc.) prior to launch of one of MAVs 14,a hardwire link 16 can be provided between USV 10 and each MAV 14.Hardwire link 16 can be an umbilical-type of link/tether that remainscoupled to MAV 14 prior to and during launch thereof, but then isuncoupled from MAV 14 once the MAV's propulsion and flight controlsystems are operational and the MAV has been launched.

Referring now to FIG. 1C, the one MAV 14 launched into the air bylauncher 12 is illustrated as being uncoupled from hardwire link 16 andflying under its own power. The video surveillance performed by theairborne one of MAVs 14 is indicated by field-of-view 18 while thewireless transmission of the video data captured is field-of-view 18 isindicated by arrow 20. Typically, wireless transmission 20 is a radiofrequency (RF) transmission that can either be received at a remotelocation or by USV 10 for storage and/or re-transmission as indicated byarrow 22. If USV 10 is to re-transmit the video data, USV 10 could beequipped with higher power SATCOM or RF transmission means. Further, ifsurface 100 is a water surface, USV 10 could be equipped with acousticor other underwater communications systems capable of transmittingsignals 24 under (water) surface 100.

The above-described process can be repeated for each of the remainingMAVs 14 that are still coupled to USV 10. As illustrated in FIG. 1D, asecond MAV 14 can be launched into the air when, for example, i) videoreconnaissance of a different area is required, ii) the first launchedMAV 14 runs out of power or otherwise fails, or iii) a communicationrelay/is needed to support transmission of video data 20 from the firstand/or second launched MAV 14.

Referring additionally now to FIG. 2, an embodiment of USV 10 forsupporting the above-described operational scenario is shown in blockdiagram form. At the heart of USV 10 is a controller 110 thatorchestrates all activity onboard USV 10. More specifically, controller110 performs navigation functions, controls motion of USV 10, commandslaunches of MAVs 14, oversees image data communications and video datatransmissions, and controls video data storage/retrieval. Controller 110can be realized by one central control computer or by individual controlcomputers for each major function performed by USV 10.

In terms of navigation and motion of USV 10, navigation sensor(s) 112are coupled to controller 110 and can include a compass for readingvehicle headings, wheel encoders for measuring distance traveled, a GPSreceiver, and inertial sensors. Readings from these sensor/receivers areused by controller 110 in ways well known in the art (e.g., GPS receiverprovides long baseline navigation while compass, wheel encoders andinertial sensors are used for dead reckoning) to determine an accurateposition of USV 10 at all times. Controller 110 uses the determinedposition to adjust a steering and drive system 114 so that USV 10 isnavigated along a desired path to a destination. The desired path anddestination can be pre-programmed into controller 110 in which case USV10 moves in a completely autonomous fashion. Another option is tocontrol USV 10 from a remote location. Accordingly, a communicationsmodule 116 can include separate communications 116A and 116B wherecommunications 116A is used to communicate between MAVs 14 andcommunications 116B is used to communicate with a remote location.Ideally, both communications can occur simultaneously and uninterrupted.

Environmental sensor(s) 118 can include sensors for collecting dataabout the environment in which USV 10 resides (e.g., motion, acoustic,seismic, temperature, video, etc.) as well as sensors used during themovement of USV 10 (e.g., collision sensing, collision avoidance, video,etc.). For example, once USV 10 reaches its desired destination,controller 110 can place itself and systems coupled thereto in a “sleep”mode to conserve power while environmental sensor(s) 118 “listen” forenvironment changes that signal the need for reconnaissance, at whichpoint controller 110 wakes the needed onboard systems. The collecteddata could also be stored onboard USV 10 using data storage 120.

Controller 110 is coupled to launcher 12 and is also coupled to each MAV14 (only one of which is shown in FIG. 2) via hardwire link 16. Asmentioned above, hardwire link 16 is used to activate and check thevarious flight systems onboard MAV 14 prior to the launching thereof bylauncher 12.

Referring to FIG. 3, an embodiment of MAV 14 for supporting thereconnaissance aspect of the present invention is shown in block diagramform. A controller 140 oversees all of the functions of MAV 14 that caninclude autonomous flight control, remote-operator controlled flight,communications, video surveillance and data storage. In terms of itsflying operations, MAV 14 includes navigation sensor(s) 142 (e.g.,compass, altimeter, GPS, inertial, etc.) for providing positioninformation to controller 140 which, in turn, uses such position toimplement a flight plan using the MAV's propulsion and flight control144 (e.g., motor or engine, propeller, control surfaces, etc.) Theflight plan can be pre-programmed into controller 140 or could beprovided remotely from USV 10 or some other location. Accordingly, acommunications module 146 can include communications 146A forcommunication with a remote base location (that can be in the air, onthe ground or on the water) and communications 146B for communicationwith just USV 10. Since two-way communication would be required, each ofcommunications 146A and 146B can be realized by an RF transceiver.

Once MAV 14 is airborne, controller 140 activates video surveillance 148which typically includes a miniature camera (e.g., standard image,thermal starlight, etc.) and video processor. The video data is passedto controller 140 which can store some or all thereof at data storage150 and/or have some transmitted from MAV 14 using communications module146.

Controller 140 is also coupled to hardwire link 16 as described above.Just prior to launch of MAV 14, controller 140 receives wake commandsvia hardwire link 16. Such wake commands could be detailed with respectto each system onboard MAV 14 or could simply be one command thattriggers that start of an operational program stored on controller 140.At a minimum, navigation sensor (s) 142 and propulsion/flight control144 are activated prior to launch of MAV 14. Note that hardwire link 16could also be used to check the integrity of each system onboard MAV 14prior to launch thereof. Then, if a failure is detected, another one ofthe MAVs 14 could be launched.

As mentioned above, the present invention could also function as acommunications system with the hardware provided on each of USV 10 andMAVs 14 being the same as the already described. Accordingly,simultaneous reference will be made to FIGS. 1–3 in order to explain theoperation of the present invention's use as a communications system. Inessence, data collected autonomously by USV 10 over a period of time istransmitted by an airborne one of MAVs 14. Thus, no personnel need bepresent to perform data collection and line-of-sight transmissiondistance is greatly increased by the airborne MAV 14.

The data collected by USV 10 (e.g., by its environmental sensor(s) 118)can be transferred to one of MAVs 14 for airborne transmission therefromin one of two ways. First, collected data could be stored onboard USV 10using data storage 120. Then, when one of MAVs 14 is airborne, thecollected data could be transmitted thereto using the communicationslink formed by the combination of communications 116A and 146B. MAV 14would then re-transmit the data using communications 146A. Note that theuse of separate communications links allows the data to be relayednearly simultaneously.

The second way collected data could be transferred to one of MAVs 14involves storing the collected data onboard MAV 14 (using data storage150) prior to launching MAV 14. Then, at a predetermined time, or whendata storage 150 is at capacity, MAV 14 is launched into the air wheretransmission to a remote location occurs using communications 146A. Onceairborne, transfer of collected data to MAV 14 could then occur asdescribed in the first method. Note that USV 10 could simultaneouslystore the collected data using data storage 120 for archive purposes,for re-transmission, or if the airborne one of MAVs 14 experiences afailure.

The present invention's communication aspect could also use USV 10 as adata collection node for a large number of surface-based reconnaissancevehicles. This scenario is depicted in FIG. 4 where USV 10 is deployedat earth surface 100 and is equipped as previously described. Deployedon surface 100 (or under surface 100 in the case of a water environment)are a number of surveillance vehicles 11, each of which is equipped withsensor(s) 11A for sensing information such as environmental conditionsand communications 11B for transferring sensed information to USV 10. Insituations where surveillance vehicles 11 are on a ground or watersurface, communications 11B can be RF communications that transmit theinformation for receipt by (RF) communications 116B onboard USV 10.However, if surveillance vehicles are deployed underwater,communications 11B can be an acoustic transmitter and communications116B can be an acoustic receiver (or transceiver if two-waycommunication with surveillance vehicles 11 is required). Theinformation collected by USV 10 in this fashion can then be transferredto an MAV 14 for airborne transmission thereof as described above.

The advantages of the present invention are numerous. Personnel are keptout of dangerous, remote and/or time consuming data reconnaissancesituations. Thus, the present invention is safer and cheaper thanexisting personnel-based reconnaissance and/or communications system.The use of high-cost satellite communications is not required. Further,by equipping each USV with multiple MAVs, the present invention presentsa long-term solution to providing covert reconnaissance and improvedlong-range communications with unmanned reconnaissance vehicle(s).

Although the invention has been described relative to a specificembodiment thereof, there are numerous variations and modifications thatwill be readily apparent to those skilled in the art in light of theabove teachings. For example, USV 10 could remain underwater at alltimes with launcher 12 being a buoyant platform that could be releasedfrom USV 10. Upon such release, the buoyant launching platform wouldfloat to the water's surface, launch it's MAV(s), and then be scuttledand sink below the water's surface. It is therefore to be understoodthat, within the scope of the appended claims, the invention may bepracticed other than as specifically described.

1. A communications system, comprising: an unmanned surface vehicle(USV) capable of movement on an earth surface, said USV having datacollection means for collecting data about an environment in which saidUSV resides; at least one micro-aerial vehicle (MAV) equipped forunmanned flight after a launch thereof, said MAV mounted on said USV andhaving radio frequency (RF) communication means mounted thereon; andlaunching means mounted on said USV for launching said MAV into the air,wherein said MAV so-launched into the air transmits said data using saidRF communication means.
 2. A communications system as in claim 1 whereinsaid USV further comprises an RF transceiver for transmitting said datato said RF communications means associated with said MAV so-launched. 3.A communications system as in claim 2 further comprising surveillancevehicles in the vicinity of said USV, each of said surveillance vehiclesbeing equipped with means for transferring information therefrom to saidUSV wherein said information becomes at least a portion of said dataso-collected by said USV.
 4. A communications system as in claim 2wherein said earth surface is a water surface, said USV furtherincluding acoustic communication means coupled to said RF transceiver,and said communications system further comprising unmanned underwatervehicles (UUVs) under the water surface and in the vicinity of said USV,each of said UUVs being equipped with an acoustic transmitter fortransmitting information therefrom through the water to said acousticcommunication means of said USV wherein said information becomes atleast a portion of said data so-collected by said USV.
 5. Acommunications system as in claim 2 further comprising surveillancevehicles in the vicinity of said USV, each of said surveillance vehiclesbeing equipped with an RF transmitter for transmitting informationtherefrom to said RF transceiver of said USV wherein said informationbecomes at least a portion of said data so-collected by said USV.
 6. Acommunications system as in claim 2 wherein said RF communications meanscomprises: a first RF transceiver for two-way communication with said RFtransceiver of said USV; and a second RF transceiver for two-waycommunication with a location that is remote with respect to said USV,wherein said first RF transceiver and said second RF transceiver canoperate simultaneously.
 7. A communications system as in claim 1 whereinsaid MAV further includes data storage means coupled to said datacollection means and to said RF communications means, wherein said datais transferred from said data collection means to said data storagemeans prior to launching said MAV and wherein, after launching said MAV,said data is transmitted from said data storage means associated withsaid MAV so-launched using said RF communication means associated withsaid MAV so-launched.
 8. A method of communication between an unmannedsurface vehicle (USV) and a location that is remote with respect to USV,comprising the steps of: using said USV as a node for the collection ofdata; providing at least one micro-aerial vehicle (MAV) on said USV,said MAV being equipped for unmanned flight after a launch thereof, saidMAV having radio frequency (RF) communication means mounted thereon;launching said MAV into the air from said USV; and transmitting saiddata using said RF communication means on said MAV so-launched into theair.
 9. A method according to claim 8 wherein said step of transmittingcomprises the steps of: providing an RF transceiver on said USV; andtransmitting said data to said RF communications means associated withsaid MAV so-launched into the air using said RF transceiver on said USV.10. A method according to claim 9 further comprising the steps of:providing surveillance vehicles in the vicinity of said USV, each ofsaid surveillance vehicles being equipped with means for transmittinginformation therefrom; and transmitting said information from each ofsaid surveillance vehicles to said USV wherein said information becomesat least a portion of said data so-collected by said USV.
 11. A methodaccording to claim 9 wherein said earth surface is a water surface, saidmethod further comprising the steps of: providing said USV with acousticcommunication means coupled to said RF transceiver; providing unmannedunderwater vehicles (UUVs) under the water surface and in the vicinityof said USV, each of said UUVs being equipped with an acoustictransmitter; and transmitting information from each said acoustictransmitter through the water to said acoustic communication means ofsaid USV wherein said information becomes at least a portion of saiddata so-collected by said USV.
 12. A method according to claim 9 furthercomprising the steps of: providing surveillance vehicles in the vicinityof said USV, each of said surveillance vehicles being equipped with anRF transmitter; and transmitting information from each of saidsurveillance vehicles to said RF transceiver of said USV wherein saidinformation becomes at least a portion of said data so-collected by saidUSV.
 13. A method according to claim 9 wherein said RF communicationsmeans comprises a first RF transceiver for two-way communication withsaid RF transceiver of said USV and a second RF transceiver for two-waycommunication with a location that is remote with respect to said USV,said method further comprising the step of operating said first RFtransceiver and said second RF transceiver simultaneously.
 14. A methodaccording to claim 8 further comprising the steps of: providing said MAVwith data storage means coupled to said RF communications means and tosaid data collection means of said USV prior to launching said MAV;transferring said data from said data collection means to said datastorage means prior to launching said MAV; and transmitting with saidMAV so-launched.